Nice Criollo knife. The scabbard is likely an upgrade it happens to fit.
see
Gaucho Knives
The rich ranchers used the fancy silver mounted and scabbarded ones, the common gauchos used the wood gripped leather sheathed ones like mine below. The richer gaucho might have a silver one for dress-up days.
I include a slightly larger version in one shot, along with the wood gripped utility criollo, It's a more belligerent design. Scabbards are designed to slip behind a sash or belt.